Heat a grill pan. Grill the jalapeÃÂ±os until charred. Stem and seed the jalapeÃÂ±os; finely dice 2 of them. Thinly slice the remaining jalapeÃÂ±o and reserve on a platter.

In a saucepan, heat 2 tablespoons of olive oil. Add the diced jalapeÃÂ±os and onion and the garlic and cook over moderate heat until golden, 10 minutes. Add the tomatillos and cook until softened. Transfer to a bowl and let cool. Stir in the avocado, cilantro, and lime juice; season with salt and pepper.

Oil the chorizo and grill over moderate heat until cooked through. Remove the chorizo casing and crumble the meat into a bowl. Lightly oil the cheese and grill for 1 minute per side, then oil the pan and grill the sliced onion until charred; transfer both to the platter.

Oil the steak; season with salt and pepper. Grill over moderately high heat, turning once, 8 minutes for medium-rare. Transfer to a board and let rest for 5 minutes. Thinly slice the steak and serve with the accompaniments.